I have one user complains that his OOF stops working about half an hour after he configured it in OWA. Now I found out it's apparantely an issue with BES and Exchange 2007 SP1. User is using Outlook 2003 SP3 but OOF is done via OWA.

I checked the BES server and it's running 4.1.5.26 or 4.1.5 (Bundle 79), I assume I don't have MR1 installed. Am I better off installing SP6 instead? After that should I patch it up to MR4 as well?

Also, this will be my first major maintenance release upgrade, I assume there's no need to re-activate users once they receive the new 'service books' from BES server? In other words, if it goes well, users will not need to do anything from their end, providing they understand there will be interruption during the upgrade.